Sound output device

ABSTRACT

A sound output device includes: a speaker unit that has a sound emitting portion; an attaching member by which the speaker unit is attached to an object; a separating member that is provided between the speaker unit and the attaching member to separate the speaker unit from the attaching member; and a sealing member that is provided between the speaker unit and the attaching member to reduce a sound that is emitted from a side of the speaker unit opposite to the sound emitting portion and is transmitted to a sound emitting portion side. The attaching member has a first portion on a side of the sound emitting portion of the speaker unit, and the first portion of the attaching member has an opening that corresponds to the sound emitting portion.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention concerns technology relating to a sound outputdevice.

Description of the Related Art

In a system that facilitates a hands-free call in a car, for example, aloudspeaker that has a built-in speaker unit and microphone is directlyattached to the interior of the car (e.g., WO 2014/203380 A1).

According to the technology described in WO 2014/203380 A1, however,since the loudspeaker is directly attached to the interior of the car,when a user makes a hands-free call, vibrations generated by theloudspeaker attached to the car's interior in turn vibrate the interior,in some cases resulting in noise.

SUMMARY OF THE INVENTION

The present invention is created in view of the above circumstances andan object of the invention is to provide a sound output device capableof reducing vibrations of the interior due to vibrations generated by aloudspeaker.

In order to achieve the above-mentioned objective, a sound output deviceaccording to a first aspect of the present invention includes: a speakerunit that has a sound emitting portion; an attaching member by which thespeaker unit is attached to an object; a separating member that isprovided between the speaker unit and the attaching member to separatethe speaker unit from the attaching member; and a sealing member that isprovided between the speaker unit and the attaching member to reduce asound that is emitted from a side of the speaker unit opposite to thesound emitting portion and is transmitted to a sound emitting portionside. The attaching member has a first portion on a side of the soundemitting portion of the speaker unit, and the first portion of theattaching member has an opening that corresponds to the sound emittingportion. One end of the separating member is attached to the speakerunit and the other end of the separating member is attached to theattaching member, and one end of the sealing member is attached to thespeaker unit and the other end of the sealing member is attached to theattaching member.

A sound output device according to a second aspect of the presentinvention includes: a speaker unit that has a sound emitting portion; anattaching member by which the speaker unit is attached to an object; anda separating member that is provided between the speaker unit and theattaching member to separate the speaker unit from the attaching member.The separating member reduces a sound that is emitted from a side of thespeaker unit opposite to the sound emitting portion and is transmittedto a sound emitting portion side. One end of the separating member isattached to the speaker unit and the other end of the separating memberis attached to the attaching member. The attaching member has a firstportion on a side of the sound emitting portion of the speaker unit, andthe first portion of the attaching member has an opening thatcorresponds to the sound emitting portion.

A sound output device according to a third aspect of the presentinvention includes: a chassis that houses a speaker unit that has asound emitting portion; an attaching member by which the chassis isattached to an object; and separating members that are provided betweenthe chassis and the attaching member to separate the chassis from theattaching member. The chassis has a first portion on a side of the soundemitting portion of the speaker unit, the attaching member has a firstportion on a side of the sound emitting portion of the speaker unit, andthe first portion of the chassis and the first portion of the attachingmember each have an opening that corresponds to the sound emittingportion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a schematic configuration of asound output device 1 according to a first embodiment.

FIG. 2A is a schematic view of the back of the sound output device 1according to the first embodiment.

FIG. 2B is a schematic view of the left side of the sound output device1.

FIG. 2C is a schematic view of the top of the sound output device 1.

FIG. 2D is a schematic view of the right side of the sound output device1.

FIG. 2E is a schematic view of the front of the sound output device 1.

FIG. 2F is a schematic view of the base of the sound output device 1.

FIG. 3A is a schematic view of the back of a loudspeaker 3 according tothe first embodiment.

FIG. 3B is a schematic view of the left side of the loudspeaker 3.

FIG. 3C is a schematic view of the top of the loudspeaker 3.

FIG. 3D is a schematic view of the right side of the loudspeaker 3.

FIG. 3E is a schematic view of the front of the loudspeaker 3.

FIG. 3F is a schematic view of the base of the loudspeaker 3.

FIG. 4 is a perspective view showing a schematic configuration of theloudspeaker 3 according to the first embodiment.

FIG. 5A is an illustration showing a front board of an outer box 2viewed from a back board side.

FIG. 5B is a cross-sectional view along line A-A shown in FIG. 2C.

FIG. 5C is an illustration showing the back board of the outer box 2viewed from a front board side.

FIG. 6 is an exploded view of the view shown in FIG. 5B.

FIG. 7A is a schematic diagram of the sound output device 1 according tothe first embodiment.

FIG. 7B is another schematic diagram of the sound output device 1according to the first embodiment.

FIG. 8A is a schematic diagram of a sound output device 1 according tomodification mode 1.

FIG. 8B is another schematic diagram of the sound output device 1according to the modification mode 1.

FIG. 9A is a schematic diagram of a sound output device 1 according tomodification mode 2.

FIG. 9B is another schematic diagram of the sound output device 1according to the modification mode 2.

FIG. 10 is an illustration showing an analytical model of a sound outputdevice 1 in a second embodiment.

FIG. 11 shows an equivalent circuit of the analytical model shown inFIG. 10.

FIG. 12A is an exploded view of the cross-sectional view of a soundoutput device 1 according to a third embodiment.

FIG. 12B is a cross-sectional view of the sound output device 1according to the third embodiment.

FIG. 13 is a schematic front view of a sound output device 1 accordingto a fourth embodiment.

FIG. 14 is a schematic diagram of the sound output device 1 according tothe fourth embodiment.

FIG. 15 is an illustration showing a schematic configuration of a soundoutput device 1 according to modification mode 1.

FIG. 16 is a schematic diagram of a sound output device 1 according tomodification mode 2.

FIG. 17 is a schematic diagram of a sound output device 1 according tomodification mode 3.

DESCRIPTION OF THE EMBODIMENTS

In the following, embodiments of the invention are described withreference to accompanying drawings.

First Embodiment

FIG. 1 is a perspective view showing a schematic configuration of asound output device 1 according to a first embodiment. FIGS. 2A to 2Fshow a schematic configuration of the sound output device 1 according tothe first embodiment. Of the sound output device 1, FIG. 2A shows a backview, FIG. 2B shows a left side view, FIG. 2C shows a top view, FIG. 2Dshows a right side view, FIG. 2E shows a front view, and FIG. 2F shows abase view. As shown in these figures, the sound output device 1 includesan outer box 2 (attaching member), a loudspeaker 3, and a microphone 4.The loudspeaker 3 includes a speaker unit 30 that has a sound emittingportion 30 a and an inner box 32 (chassis) that houses the speaker unit30 (detailed configuration of the loudspeaker 3 is described later). Thespeaker unit 30 emits sounds in accordance with supplied audio signals.The sound emitting portion 30 a is a portion (e.g., diaphragm), of thespeaker unit 30, that vibrates in accordance with audio signals togenerate sounds.

As shown in these figures, an X-Y plane that includes the rim of thesound emitting portion 30 a of the speaker unit 30 (hereinafter, may bereferred to as a sound emitting plane) and a Z-axis perpendicular to theX-Y plane are assumed. The Z-axis direction corresponds to thecentral-axis direction of the speaker unit 30. A rear portion 30 b ofthe speaker unit 30, which is on the side opposite to the sound emittingportion 30 a, is on the positive side relative to the sound emittingportion 30 a in the Z-axis direction. A portion of the speaker unit 30other than the sound emitting portion 30 a and the rear portion 30 b isreferred to as a sidewall 30 c of the speaker unit 30.

The outer box 2 has a front board 2 a, a back board 2 b, and multiple(four pieces of) side boards 2 c. The front board 2 a, the back board 2b, and the side boards 2 c are each a substantially rectangular tabularmember. The four side boards 2 c are disposed, between the mutuallyfacing front board 2 a and back board 2 b, along the sides of the frontboard 2 a and those of the back board 2 b to form the hollow cuboidalouter box 2. The front board 2 a and the back board 2 b are eachparallel to the sound emitting plane, and the side boards 2 c areparallel to the Z-axis. The front board 2 a is on the negative siderelative to the back board 2 b in the Z-axis direction. The front board2 a (first portion of the attaching member) is provided on a side of thesound emitting portion 30 a of the speaker unit 30. In the front board 2a, an opening 20 is formed that exposes the sound emitting portion 30 aof the speaker unit 30 and corresponds to the shape of the soundemitting portion 30 a. The back board 2 b (second portion of theattaching member) is provided on a side of the rear portion 30 b of thespeaker unit 30. In the back board 2 b, an opening 22 is formed thatexposes part of the back portion 32 b of the inner box 32 andcorresponds to the shape of the back portion 32 b. The side boards 2 c(third portion of the attaching member) are provided on a side of thesidewall 30 c of the speaker unit 30. In the side boards 2 c, multipleopenings 21 are formed.

A recessed portion 23 is formed on the outer surface of the front board2 a of the outer box 2 (the surface opposite the surface that is on aback board 2 b side), and the microphone 4 is placed in the recessedportion 23. The microphone 4 is, for example, an MEMS(Micro-Electrical-Mechanical Systems) microphone. It is not essentialfor the sound output device 1 in this embodiment to include themicrophone 4.

The sound output device 1 is attached to a freely chosen object, such asthe interior of a car. More specifically, the sound output device 1 isattached to the interior of a car such that the outer surface of thefront board 2 a of the outer box 2, in which board the opening 20 isformed, faces the back side of the interior. In this way, the soundemitting portion 30 a of the speaker unit 30 faces toward the inside ofthe car. In other words, the outer box 2 serves as an attaching memberthat attaches the inner box 32 to an object. An object to which theinner box 32 is attached may be, for example, the ceiling of the car'sinterior (e.g., a part near a room lamp and/or a map lamp), a dashboard,or a door.

In this and the following embodiments, it is assumed that the outer box2 has multiple boards (the front board 2 a, the back board 2 b, and theside boards 2 c) that are formed separately. However, some parts of theouter box 2 (e.g., the front board 2 a and the side boards 2 c) may beformed as one body.

FIGS. 3A to 3F show a schematic configuration of the loudspeaker 3 inthe first embodiment. Of the loudspeaker 3, FIG. 3A shows a back view,FIG. 3B shows a left side view, FIG. 3C shows a top view, FIG. 3D showsa right side view, FIG. 3E shows a front view, and FIG. 3F shows a baseview. FIG. 4 is a perspective view showing a schematic configuration ofthe loudspeaker 3 in the first embodiment. As shown in these figures,the loudspeaker 3 includes the speaker unit 30 and the inner box 32(chassis) that houses the speaker unit 30.

FIG. 7A is a schematic diagram showing an example of a cross-section ofthe sound output device 1 when the sound output device 1 is viewed fromthe positive Y-axis side. As is understood from FIG. 7A, the inner box32 has a boxlike portion and a cylindrical portion that protrudes fromthe boxlike portion toward the positive Z-axis direction. The speakerunit 30 is disposed inside the inner box 32, across from the boxlikeportion to the cylindrical portion. The inner box 32 has a front portion32 a, a back portion 32 b, and a side portion 32 c. The front portion 32a is a portion on a side of the sound emitting portion 30 a of thespeaker unit 30; i.e., a part of the boxlike portion on a sound emittingportion 30 a side. The back portion 32 b is a portion on a side of therear portion 30 b of the speaker unit 30. The back portion 32 b includesa part of the boxlike portion on a rear portion 30 b side and thecylindrical portion. The side portion 32 c is a portion other than thefront portion 32 a and the back portion 32 b, the portion being on aside of the sidewall 30 c of the speaker unit 30. That is, the sideportion 32 c is a lateral part of the boxlike portion. Each of the partof the boxlike portion on the sound emitting portion 30 a side and thepart of the boxlike portion on the rear portion 30 b side is parallel tothe sound emitting plane, and the lateral part of the boxlike portion isparallel to the central axis of the speaker unit 30.

The outer surface (the surface on the negative Z-axis side) of the frontportion 32 a of the inner box 32 is arranged on substantially the sameplane as the sound emitting plane. The outer surface (the surface on thepositive Z-axis side) of the base of the cylindrical portion of the backportion 32 b of the inner box 32 is arranged on substantially the sameplane as the outer surface (the surface on the positive Z-axis side) ofthe back board 2 b of the outer box 2. The front portion 32 a of theinner box 32 is provided on the positive Z-axis side relative to thefront board 2 a of the outer box 2. Of the back portion 32 b of theinner box 32, the part of the boxlike portion on the rear portion 30 bside is provided on the negative Z-axis side relative to the back board2 b of the outer box 2.

As shown in FIGS. 3A to 3F and FIG. 4, holding parts 33 each having, forexample, a convex shape are formed on the four corners of the outersurface of the front portion 32 a of the inner box 32 (the surfacefacing the front board 2 a of the outer box 2). Holding parts 34 eachhaving, for example, a convex shape are formed on the four corners ofthe outer surface of the back portion 32 b of the inner box 32 (thesurface facing the back board 2 b of the outer box 2). That is, theholding parts 34 are formed on the four corners of the outer surface ofthe part of the boxlike portion of the inner box 32 on the rear portion30 b side. As shown in FIG. 3C, in the front portion 32 a of the innerbox 32 (first portion of the chassis), there is formed an opening 35that exposes the sound emitting portion 30 a of the speaker unit 30 andcorresponds to the shape of the sound emitting portion 30 a.

The parts of the inner box 32 (the front portion 32 a, the back portion32 b, and the side portion 32 c) may be formed separately and thenassembled, or some parts of the inner box 32 (e.g., the front portion 32a and the side portion 32 c) may be formed as one body.

FIG. 5A is an illustration showing the inner surface (the surface on aninner box 32 side) of the front board 2 a of the outer box 2. FIG. 5C isan illustration showing the inner surface (the surface on a side of theboxlike portion of the inner box 32) of the back board 2 b of the outerbox 2. As shown in these figures, holding parts 24 each having, forexample, a concave shape are formed on the four corners of the innersurface of the front board 2 a, and holding parts 25 each having, forexample, a concave shape are formed on the four corners of the innersurface of the back board 2 b. FIG. 5B is a cross-sectional view alongline A-A shown in FIG. 2C from the positive Y-axis side. FIG. 6 is anexploded view, along the Z-axis, of the cross-section shown in FIG. 5B.

As shown in FIG. 5B and FIG. 6, vibration dampers 50 (separatingmembers) lie between the holding parts 33 and the holding parts 24, withthe holding parts 33 being formed on the outer surface of the frontportion 32 a of the inner box 32 of the loudspeaker 3, and the holdingparts 24 being formed on the inner surface of the front board 2 a of theouter box 2. Additionally, vibration dampers 51 (separating members) liebetween the holding parts 34 and the holding parts 25, with the holdingparts 34 being formed on the outer surface of the back portion 32 b ofthe inner box 32 (more precisely, the part of the boxlike portion of theinner box 32 on the rear portion 30 b side), and the holding parts 25being formed on the inner surface of the back board 2 b of the outer box2. The vibration dampers 50 and 51 are members that lie between theinner box 32 and the outer box 2, separating them to absorb vibrationsof the loudspeaker 3. In the following, the description of the holdingparts (24, 25, 33, and 34) may be omitted for brevity. For example, thedescription that “the vibration dampers 50 (or 51) lie between the frontboard 2 a (or the back board 2 b) of the outer box 2 and the frontportion 32 a (or the back portion 32 b) of the inner box 32” means that“the vibration dampers 50 (or 51) lie between the holding parts 24 (or25) on the outer box 2 and the holding parts 33 (or 34) on the inner box32.”

As shown in FIG. 5A and FIG. 5B, inside the outer box 2, there may beprovided a signal processing IC 60 that executes sound processing onaudio signals provided to the speaker unit 30, such processing includingamplification of, or addition of sound effects to, the audio signals.

As shown in FIG. 7A, the vibration dampers 50 are disposed between thefront board 2 a of the outer box 2 and the front portion 32 a of theinner box 32. Accordingly, the front portion 32 a of the inner box 32and the sound emitting portion 30 a are disposed behind the front board2 a of the outer box 2. The vibration dampers 51 are disposed betweenthe back portion 32 b of the inner box 32 (more precisely, the boxlikeportion corresponding to the back portion 32 b) and the back board 2 bof the outer box 2. Thus, in FIG. 7A, the length d1 of the outer box 2along the central-axis direction of the speaker unit 30 (Z-axisdirection) is greater than the length d3 of the speaker unit 30. Morespecifically, in the central-axis direction of the speaker unit 30, thefront board 2 a of the outer box 2 is on the negative Z-axis siderelative to the sound emitting portion 30 a, and the back board 2 b ofthe outer box 2 is on the positive Z-axis side relative to the rearportion 30 b of the speaker unit 30. The length d2 of the inner box 32is greater than the length d3 of the speaker unit 30. More specifically,in the central-axis direction of the speaker unit 30, the outer surfaceof the front portion 32 a of the inner box 32 is on substantially thesame plane as the sound emitting plane, and the base of the cylindricalportion of the back portion 32 b of the inner box 32 is on the positiveZ-axis side relative to the rear portion 30 b of the speaker unit 30.

With the outer box 2 that serves as an attaching member, the soundoutput device 1 is attached to an object 7, which is, for example, theinterior of a car. In FIG. 7A, for the sake of brevity, only a portionof the object 7, to which the sound output device 1 is attached, isillustrated, and the illustration of the holding parts (24, 25, 33, and34), the microphone 4, the signal processing IC 60, etc. are omitted.Such simplified illustration also applies to FIG. 7B to FIG. 9B.

FIG. 7A schematically shows an exemplary configuration of the soundoutput device 1. The sound output device 1 according to the firstembodiment is not limited to the configuration shown in FIG. 7A. FIG. 7Bschematically shows another exemplary configuration of the sound outputdevice 1 according to the first embodiment. In the example shown in FIG.7B, in addition to the boxlike portion and the first cylindrical portionthat protrudes from the boxlike portion toward the positive Z-axisdirection, the inner box 32 has a second cylindrical portion thatprotrudes from the boxlike portion toward the negative Z-axis directionon a side of the sound emitting portion 30 a of the speaker unit 30.Here, the second cylindrical portion is treated as part of the frontportion 32 a of the inner box 32. The speaker unit 30 is disposed insidethe inner box 32 across from the second cylindrical portion to the firstcylindrical portion through the boxlike portion. The speaker unit 30 isdisposed such that the sound emitting plane is on substantially the sameplane as the outer surface of the front board 2 a of the outer box 2. Inthis example, as is the case in the exemplary configuration shown inFIG. 7A, the vibration dampers 50 are disposed between the front board 2a of the outer box 2 and the front portion 32 a of the inner box 32(more precisely, the boxlike portion corresponding to the front portion32 a), and the vibration dampers 51 are disposed between the back board2 b of the outer box 2 and the back portion 32 b of the inner box 32(more precisely, the boxlike portion corresponding to the back portion32 b). In the example shown in FIG. 7B, however, the sound output device1 is configured such that the length d2 of the inner box 32 issubstantially equal to the length d1 of the outer box 2. Morespecifically, the outer surface of the front board 2 a of the outer box2 and the upper-end surface of the second cylindrical portion of thefront portion 32 a of the inner box 32 are on substantially the sameplane. Additionally, the outer surface of the back board 2 b of theouter box 2 and the outer surface of the base of the first cylindricalportion of the back portion 32 b of the inner box 32 are onsubstantially the same plane.

In this embodiment, the vibration dampers 50 and 51 are provided both ona side of the front portion 32 a and on a side of the back portion 32 bof the inner box 32. However, only the vibration dampers 50 on a side ofthe front portion 32 a of the inner box 32 may be provided, or only thevibration dampers 51 on a side of the back portion 32 b of the inner box32 may be provided. In a case in which only the vibration dampers 51 ona side of the back portion 32 b of the inner box 32 are provided, theremay be provided a predetermined space between the front portion 32 a ofthe inner box 32 and the front board 2 a of the outer box 2.

In this embodiment, a coiled spring member is used as an example of avibration damper 50 or 51. One end of a vibration damper 50 is attachedto a holding part 33 formed on the front portion 32 a of the inner box32, and the other end of the vibration damper 50 is attached to aholding part 24 formed on the front board 2 a of the outer box 2. Oneend of a vibration damper 51 is attached to a holding part 34 formed onthe back portion 32 b of the inner box 32, and the other end of thevibration damper 51 is attached to a holding part 25 formed on the backboard 2 b of the outer box 2. More specifically, the convex part of a,for example, convex-shaped holding part 33 (or 34) is inserted into oneend of a spring member, and the other end of the spring member isinserted into the concave part of a corresponding, for example,concave-shaped holding part 24 (or 25).

Material used for the vibration dampers 50 and 51 is not limited to aspring and may be any material that absorbs vibrations. For a vibrationdamper, any elastic material other than a spring (e.g., sponge, resin)or any other material (e.g., gel) may be used.

In this embodiment, as described above, the inner box 32 housing thespeaker unit 30 is attached to the outer box 2 with the vibrationdampers 50 and 51 provided therebetween such that the inner box 32 isseparated from the outer box 2. In this way, when the speaker unit 30generates sounds, vibrations generated by the speaker unit will beabsorbed by the vibration dampers 50 and 51. Accordingly, in a case inwhich the sound output device 1 is attached to an object 7 (e.g., theinterior of a car), vibrations (vibrations that the speaker unit 30generates) that are transmitted to the object 7 are reduced, andconsequently, noise generated by the vibrations can be reduced.Moreover, since the vibrations transmitted to the object 7 are reduced,noise that is generated due to the vibrations and is then transmitted tothe microphone 4 adjacent to the speaker unit 30 is reduced. Thus,degradation of echo-cancellation performance can be lessened.Furthermore, in this embodiment, the vibration dampers 50 are disposedon the same side as the sound emitting portion 30 a. In this way,compared with a case in which only the vibration dampers 51 are disposedon the rear portion 30 b side, more remarkable advantageous effects areachieved in reducing the vibrations and hence the noise.

Additionally, in this embodiment, multiple openings 21 are formed in theside boards 2 c of the outer box 2, and the opening 22 that exposes partof the back portion 32 b of the inner box 32 is formed in the back board2 b of the outer box 2. In this way, even when the inner box 32 deformsdue to generation of sound, the pressure of the space between the innerbox 32 and the outer box 2 will not increase, and consequently,unnecessary distortion of the outer box 2 can be suppressed.

Modifications of First Embodiment

The sound output device 1 according to the first embodiment can bemodified in a variety of ways.

Modification Mode 1

FIG. 8A and FIG. 8B show examples of mode 1. As shown in the figures,the inner box 32 according to mode 1 has, in addition to the opening 35that exposes the sound emitting portion 30 a of the speaker unit 30 (theopening in the first portion of the chassis), an opening 36 thatcorresponds to the shape of the rear portion 30 b in the back portion 32b (second portion of the chassis) on a side of the rear portion 30 b ofthe speaker unit 30.

FIG. 8A is a modification of FIG. 7A. In the example shown in FIG. 8A,similarly to the inner box 32 shown in FIG. 7A, the inner box 32 has aboxlike portion and a first cylindrical portion (included in the backportion 32 b of the inner box 32) that protrudes from the boxlikeportion toward the positive Z-axis direction. In the example shown inFIG. 8A, the opening 36 is formed in the base of the cylindricalportion. As shown in the figure, neither the length d1 of the outer box2 nor the length d2 of the inner box 32, in the central-axis directionof the speaker unit 30, is greater than the length d3 of the speakerunit 30. More specifically, the outer surface of the front board 2 a ofthe outer box 2 and the outer surface of the front portion 32 a of theinner box 32 are each on substantially the same plane as the soundemitting plane. Additionally, the outer surface of the back board 2 b ofthe outer box 2 and the outer surface of the back portion 32 b (moreprecisely, the base of the cylindrical portion) of the inner box 32 areeach on substantially the same plane as the end surface of the rearportion 30 b of the speaker unit 30 (the rear face of the speaker unit30). In other words, the length of the sound output device 1 in thecentral-axis direction of the speaker unit 30 is substantially equal tothe length d3 of the speaker unit 30.

In the example shown in FIG. 8A, similarly to the example shown in FIG.7A, the vibration dampers 51 are provided between the back portion 32 bof the inner box 32 (more precisely, the boxlike portion correspondingto the back portion 32 b) and the back board 2 b of the outer box 2.However, in the example shown in FIG. 8A, the vibration dampers 50 arenot provided on the sound emitting portion 30 a side. Additionally, agap between the front board 2 a of the outer box 2 (first portion of theattaching member) and the front portion 32 a of the inner box 32 (firstportion of the chassis) is sealed with a sealing member 80.

The sealing member 80 is a member that reduces transmission of sounds.For example, grease, rubber, or closed-pore sponge may be used for thesealing member 80.

FIG. 8B is a modification of FIG. 7B. In the example shown in FIG. 8B,similarly to the inner box 32 described with reference to FIG. 7B, theinner box 32 has a boxlike portion, a first cylindrical portion(included in the back portion 32 b of the inner box 32) that protrudesfrom the boxlike portion toward the positive Z-axis direction, and asecond cylindrical portion (included in the front portion 32 a of theinner box 32) that protrudes from the boxlike portion toward thenegative Z-axis direction. In the example shown in FIG. 8B, however, thefirst cylindrical portion has no base. In other words, in FIG. 7B, anexemplary configuration is shown in which the end (base) of thecylindrical portion on a positive Z-axis side is closed. In theconfiguration shown in FIG. 8B, however, the base of the cylindricalportion is opened by the opening 36. In FIG. 8B, similarly to theexample shown in FIG. 8A, neither the length d1 of the outer box 2 northe length d2 of the inner box 32 is greater than the length d3 of thespeaker unit 30 in the central-axis direction of the speaker unit 30.Also, the length of the sound output device 1 is substantially equal tothe length d3 of the speaker unit 30 in the central-axis direction ofthe speaker unit 30. More specifically, in the central-axis direction ofthe speaker unit 30, the outer surface of the front board 2 a of theouter box 2 and the upper-end surface of the second cylindrical portionof the front portion 32 a of the inner box 32 are each on substantiallythe same plane as the sound emitting plane, and the outer surface of theback board 2 b of the outer box 2 and the lower-end surface of the firstcylindrical portion of the back portion 32 b of the inner box 32 areeach on substantially the same plane as the rear face of the speakerunit 30.

In FIG. 8B, similarly to the exemplary configuration shown in FIG. 7B,the vibration dampers 50 are disposed between the front board 2 a of theouter box 2 and the front portion 32 a of the inner box 32 (moreprecisely, the boxlike portion corresponding to the front portion 32 a),and the vibration dampers 51 are disposed between the back board 2 b ofthe outer box 2 and the back portion 32 b of the inner box 32 (moreprecisely, the boxlike portion corresponding to the back portion 32 b).A gap between the front board 2 a of the outer box 2 (first portion ofthe attaching member) and the front portion 32 a (more precisely, thesecond cylindrical portion of the front portion 32 a) of the inner box32 (first portion of the chassis) is sealed with a sealing member 80.Also, a gap between the back board 2 b of the outer box 2 (secondportion of the attaching member) and the back portion 32 b (moreprecisely, the first cylindrical portion of the back portion 32 b) ofthe inner box 32 (second portion of the chassis) is sealed with asealing member 80.

In the above configuration, advantageous effects similar to thoseachieved in the first embodiment are achieved. In a configuration inwhich the inner box 32 is sealed, there will be generated air springinside the inner box 32 due to compression of the air, and thus thevibrations of the sound emitting portion 30 a (e.g., diaphragm) of thespeaker unit 30 may be hampered. In the configuration according to thepresent mode, since the inner box 32 has the opening 36, air spring willnot be generated between the speaker unit 30 and the inner box 32. Thus,the sound emitting portion 30 a is able to vibrate sufficiently, whichenables easy emission of sounds having high sound pressure by thespeaker unit 30. Moreover, in the configuration according to the presentmode, the sound output device 1 is configured such that in thecentral-axis direction of the speaker unit 30, each of the length d1 ofthe outer box 2 and the length d2 of the inner box 32 is equal to orsmaller than the length d3 of the speaker unit 30. Thus, compared with aconfiguration in which at least one of the length d1 of the outer box 2or the length d2 of the inner box 32 is greater than the length of thespeaker unit (e.g., either of the exemplary configurations shown in FIG.7A and FIG. 7B), the sound output device 1 according to the present modeis reduced in size. Furthermore, since the sealing member 80 seals thegap between the outer box 2 and the inner box 32, there is a reductionin sounds that are emitted from the rear portion 30 b of the speakerunit 30, passing through the space between the outer box 2 and the innerbox 32, and then transmitted to a side of the sound emitting portion 30a of the speaker unit 30. In other words, the sneaking of the soundsemitted from the rear portion 30 b of the speaker unit 30 to the soundemitting portion 30 a side is lessened.

FIG. 8B shows an example in which each of the gap between the frontboard 2 a of the outer box 2 and the front portion 32 a of the inner box32 and the gap between the back board 2 b of the outer box 2 and theback portion 32 b of the inner box 32 is sealed by a sealing member 80.Alternatively, only the gap between the front board 2 a of the outer box2 and the front portion 32 a of the inner box 32 may be sealed, or onlythe gap between the back board 2 b of the outer box 2 and the backportion 32 b of the inner box 32 may be sealed. From a viewpoint oflessening the sneaking of sounds to the sound emitting portion 30 aside, it is preferable to seal the gap between the front board 2 a ofthe outer box 2 and the front portion 32 a of the inner box 32, on thesound emitting portion 30 a side.

Modification Mode 2

In examples of mode 2 shown in FIG. 9A and FIG. 9B, the back portion 32b of the inner box 32 (second portion of the chassis) described in theexample of the first embodiment is omitted, and the inner box 32 has astructure with the positive Z-axis side open. In other words, the innerbox 32 has a boxlike portion without a base and a cylindrical portionthat protrudes from the boxlike portion toward the negative Z-axisdirection. Similarly to mode 1, in the examples of mode 2, neither thelength d1 of the outer box 2 nor the length d2 of the inner box 32 isgreater than the length d3 of the speaker unit 30, and the length of thesound output device 1 is substantially equal to the length d3 of thespeaker unit 30 in the central-axis direction of the speaker unit 30. Inboth examples, the gap between the front board 2 a of the outer box 2(first portion of the attaching member) and the front portion 32 a ofthe inner box 32 (first portion of the chassis) is sealed with thesealing member 80.

In the example shown in FIG. 9A, in the central-axis direction of thespeaker unit 30 (in the Z-axis direction), the outer surface of thefront board 2 a of the outer box 2 and the upper-end surface of thecylindrical portion of the front portion 32 a of the inner box 32 areeach on substantially the same plane as the sound emitting plane. Theouter surface of the back board 2 b of the outer box 2 is onsubstantially the same plane as the rear face of the speaker unit 30.The end surface (which may be referred to as a rim) of the side portion32 c of the inner box 32 on the rear portion 30 b side (the sideopposite to the sound emitting portion 30 a) is on the negative Z-axisside relative to the rear portion 30 b. The sound output device 1 inthis example has vibration dampers 50 between the front board 2 a of theouter box 2 and the front portion 32 a of the inner box 32 (moreprecisely, the boxlike portion corresponding to the front portion 32 a),and has vibration dampers 51 between the back board 2 b of the outer box2 (second portion of the attaching member) and the side portion 32 c ofthe inner box 32 (third portion of the chassis). More precisely, thevibration dampers 51 are disposed between the back board 2 b of theouter box 2 and the rim of the side portion 32 c of the inner box 32.

In the example shown in FIG. 9B, the back board 2 b of the outer box 2(second portion of the attaching member) described in the example of thefirst embodiment is omitted, and the outer box 2 has a structure withthe positive Z-axis side open. In the central-axis direction of thespeaker unit 30, the outer surface of the front board 2 a of the outerbox 2 and the upper-end surface of the cylindrical portion of the frontportion 32 a of the inner box 32 are each on substantially the sameplane as the sound emitting plane. The end surfaces of the side boards 2c of the outer box 2 on the rear portion 30 b side and the end surfaceof the side portion 32 c of the inner box 32 on the rear portion 30 bside are each on substantially the same plane as the rear face of thespeaker unit 30. The sound output device 1 in this example includesvibration dampers 50 between the front board 2 a of the outer box 2 andthe front portion 32 a of the inner box 32 (more precisely, the boxlikeportion corresponding to the front portion 32 a).

In the above configuration, advantageous effects similar to thoseachieved in the first embodiment are achieved. Additionally, since theinner box 32 housing the speaker unit 30 does not have a back portion 32b (since the positive Z-axis side of the inner box 32 is open), comparedwith a configuration in which the inner box is sealed, the speaker unit30 is able to emit sounds having high sound pressure with ease.

Moreover, since the positive Z-axis side of the inner box 32 is open,the sound output device 1 can be configured such that, in thecentral-axis direction of the speaker unit 30, each of the length d1 ofthe outer box 2 and the length d2 of the inner box 32 is equal to orsmaller than the length d3 of the speaker unit 30. Thus, compared with aconfiguration in which at least one of the length d1 of the outer box 2or the length d2 of the inner box 32 is greater than the length of thespeaker unit (e.g., either of the configurations shown in FIG. 7A andFIG. 7B), the sound output device 1 in this mode is reduced in size.Furthermore, since the gap between the front board 2 a of the outer box2 and the front portion 32 a of the inner box 32 is sealed with thesealing member 80, sounds that are emitted from the rear portion 30 b ofthe speaker unit 30, passing through the space between the outer box 2and the inner box 32, and transmitted to a side of the sound emittingportion 30 a are reduced. In other words, the sneaking of the soundsemitted from the rear portion 30 b of the speaker unit 30 to the soundemitting portion 30 a side is lessened.

In the examples shown in FIG. 8A to FIG. 9B, a space in the object 7 towhich the sound output device 1 is attached can serve as an enclosurethat lessens the sneaking of the sounds emitted from the rear portion 30b of the speaker unit 30 to the sound emitting portion 30 a side (thesneaking of the sounds passing through the outside of the outer box 2).Here, the object 7 is, for example, the interior of a car, and the spacein the object 7 is, for example, the space inside the interior of thecar.

In FIG. 8A to FIG. 9B, examples are shown in which the length d1 of theouter box 2 and the length d2 of the inner box 32 are substantiallyequal to the length d3 of the speaker unit 30. However, each of thelength d1 of the outer box 2 and the length d2 of the inner box 32 maybe freely modified to the extent that the length of the sound outputdevice 1 does not exceed the length d3 of the speaker unit 30.

The inner box 32 may have the side portion 32 c alone. In this case, thevibration dampers 50 may be disposed between the front board 2 a of theouter box 2 and the end surface (rim) of the side portion 32 c of theinner box on the sound emitting portion 30 a side, and the vibrationdampers 51 may be disposed between the back board 2 b of the outer box 2and the end surface (rim) of the side portion 32 c of the inner box 32on the rear portion 30 b side.

In a case in which the sealing member 80 serves to reduce vibrationsthat are transmitted from the inner box 32 to the outer box 2, the soundoutput device 1 may be provided with the sealing member 80 alone,without the vibration dampers 50 and 51. In other words, the sealingmember 80 may serve in place of the vibration damper (it can also beunderstood that the vibration dampers 50 and 51 may serve as sealingmembers 80). In this case, the sealing members 80 may be disposed at thepositions of the vibration dampers 50 and 51, instead of the positionshown in the figures. In a case in which the vibration dampers 50 and 51serve as the sealing members 80, in order to lessen the sneaking of thesounds emitted from the rear portion 30 b of the speaker unit 30 to thesound emitting portion 30 a side, the vibration dampers 50 and 51 are toseal gaps between the outer box 2 and the inner box 32 (e.g., a gapbetween the front board 2 a and the boxlike portion corresponding to thefront portion 32 a, a gap between the back board 2 b and the boxlikeportion corresponding to the back portion 32 b, etc.).

In the above examples, the outer box 2 is box-shaped. However, the outerbox 2 may be of any shape so long as it attaches the inner box 32 viathe vibration dampers. For example, the outer box may be tabular orcolumn-shaped. In a case in which the outer box 2 is tabular, the frontboard 2 a corresponds to the first portion of the attaching member. In acase in which the outer box 2 is column-shaped with its central axisparallel to the Z-axis, a face of the column on the sound emittingportion 30 a side corresponds to the front board 2 a (first portion ofthe attaching member), and a face of the column on the rear portion 30 bside corresponds to the back board 2 b (second portion of the attachingmember), and a cylindrical part of the column corresponds to the sideboards 2 c (third portion of the attaching member).

Similarly, in the above examples, the front portion 32 a and the sideportion 32 c of the inner box 32 are tabular. However, the side portion32 c may be any other shape, such as tubular. More specifically, theinner box 32 may be column-shaped with its central axis parallel to theZ-axis. In this case, a face of the column on the sound emitting portion30 a side corresponds to the front portion 32 a (first portion of thechassis), a face of the column on the rear portion 30 b side correspondsto the back portion 32 b (second portion of the chassis), and acylindrical part of the column corresponds to the side portion 32 c(third portion of the chassis).

Second Embodiment

With reference to FIG. 10 and FIG. 11, a second embodiment of theinvention will be described. In each embodiment described below as anexample, for those elements that are common with those in the firstembodiment in their effects and functions, the same reference signs asthose used in the description of the first embodiment will be used, anddetailed explanations thereof will be omitted as appropriate.

FIG. 10 shows an analytical model of a sound output device 1 accordingto the second embodiment. FIG. 11 shows an equivalent circuit of theanalytical model. The speaker unit 30 has a movable portion 301 thatemits sounds with vibrations, a non-movable portion 302, and an elasticmember 303 that connects the movable portion 301 and the non-movableportion 302. The movable portion 301 includes, for example, a diaphragm(the sound emitting portion 30 a) and a voice coil that transmitsvibrations to the diaphragm. The non-movable portion 302 includes, forexample, a frame that secures the diaphragm and the voice coil. Theelastic member 303 is, for example, a speaker surround that connects thediaphragm and the frame.

As in the analytical model shown in FIG. 10, the mass of the movableportion 301 is referred to as Ls, the compliance of the air inside theinner box 32 is referred to as Ca, the compliance of the elastic member303 is referred to as Cs, the total mass of the inner box 32 and thenon-movable portion 302 is referred to as Lb, and the total resistancecomponent of the inner box 32 and the non-movable portion 302 isreferred to as Rb. The compliance of the vibration dampers 50 isreferred to as Cb, the total mass of the outer box 2 and the object 7(e.g., the interior of a car) to which the sound output device 1 isattached is referred to as Lm, the total compliance of the outer box 2and the object 7 is referred to as Cm, and the total resistancecomponent of the outer box 2 and the object 7 is referred to as Rm.

The sound output device 1 in this embodiment can be expressed as anequivalent circuit as shown in FIG. 11. In FIG. 11, Vs indicates thepower to drive the movable portion 301, and Im indicates the vibrationvelocity at the outer box 2 and the object 7. In the equivalent circuitshown in FIG. 11, the total mass Lb of the inner box 32 and thenon-movable portion 302 and the compliance Cb of the vibration dampers50 together form a low-pass filter. The resonant frequency generated bythe mass Ls of the movable portion 301, the compliance Cs of the elasticmember 303, and the compliance Ca of the air inside the inner box 32, isreferred to as f1. The cutoff frequency of the low-pass filter, which isformed by the total mass Lb of the inner box 32 and the non-movableportion 302 and the compliance Cb of the vibration dampers 50, isreferred to as f2. In this embodiment, the resonant frequency f1 and thecutoff frequency f2 are designed to satisfy the relationship f2<f1.

According to this embodiment, vibrations of the speaker unit 30 (movableportion 301) that are transmitted to the outer box 2 are reduced by thelow-pass filter, which is formed by the total mass Lb of the inner box32 and the non-movable portion 302 and the compliance Cb of thevibration dampers 50. Thus, vibrations of the speaker unit 30 that aretransmitted to the surroundings of the microphone 4 are reduced.Moreover, since noise that is generated by the vibrations is reduced(that is, noise transmitted to the microphone 4 is reduced),echo-cancellation performance can be improved.

Third Embodiment

With reference to accompanying drawings, a third embodiment of theinvention will be described next.

FIG. 12A is an exploded view, along the Z-axis, of a cross-section of asound output device 1 according to the third embodiment. FIG. 12B is across-sectional view of the sound output device 1 of the thirdembodiment. As shown in FIG. 12A, in this embodiment, two types ofsprings are used for vibration dampers provided on a side of the frontportion 32 a of the inner box 32. In other words, in addition to thespring members used as the vibration dampers 50 in the first embodiment,other spring members (vibration dampers 52) are provided. The vibrationdampers 52 have a larger spring constant than the spring members thatare used as the vibration dampers 50. On the inner surface of the frontboard 2 a of the outer box 2 (the surface on a side of the front portion32 a of the inner box 32), there are formed holding parts 26, and oneend of each vibration damper 52 is attached to a corresponding one ofthe holding parts 26. More specifically, one end of a vibration damper52 is inserted into the concave part of the corresponding, for example,concave-shaped holding part 26.

As shown in FIG. 12B, under normal conditions, the other ends of thevibration dampers 52 are not in contact with the front portion 32 a ofthe inner box 32. When an excessive acceleration caused by vibrations isapplied to the inner box 32, the other ends of the vibration dampers 52come into contact with the front portion 32 a of the inner box 32. Inthis way, with the provision of the vibration dampers 52, a collisionbetween the inner box 32 and the front board 2 a of the outer box 2,which could otherwise be caused when the inner box 32 vibrates, can beprevented.

As described above, in this embodiment, two types of spring members(vibration dampers) with varying spring constants are provided on thefront portion 32 a of the inner box 32. Thus, even when an excessiveacceleration is applied to the inner box 32, a collision between theinner box 32 and the outer box 2 can be prevented, and consequently,noise that is caused by such collision can be reduced.

Instead of using two types of spring members, non-linear springs may beused as the vibration dampers 50. For example, springs that are madewith spring members coiled into conical shape and have a spring constantthat becomes greater (springs that become stiffer) with increasing loadsmay be used. Alternatively, non-linear springs that are made with springmembers coiled into column shape with varying turn density may be used.In a case in which such non-linear springs are used, when an excessiveacceleration is applied to the inner box 32, the spring constantincreases before the inner box 32 comes into contact with the innersurface of the outer box 2, and thus, a collision between the inner box32 and the outer box 2 will be prevented. As a result, noise that couldbe generated by such collision between the inner box 32 and the outerbox 2 can be reduced.

Also in this embodiment, material used for the vibration dampers thatabsorb vibrations may be an elastic material other than springs (e.g.,resin or sponges with varying hardness), or any material other thanelastic material (e.g., gel). Alternatively, elastic material andanother material may be used in combination as appropriate (e.g., aspring and a sponge, a sponge and gel).

Fourth Embodiment

Next, with reference to FIG. 13 and FIG. 14, a fourth embodiment of theinvention will be described.

In the first to the third embodiments, examples are shown in which thesound output device 1 includes the inner box 32 (chassis) that housesthe speaker unit 30 and the vibration dampers 50 and 51 lie between theouter box 2 (attaching member) and the inner box 32. In contrast, asound output device 1 according to the fourth embodiment does notinclude the inner box 32, and the vibration dampers 50 lie between theattaching member and the speaker unit 30.

FIG. 13 is a front view of the schematic configuration of the soundoutput device 1 of the fourth embodiment. The sound output device 1 ofthe fourth embodiment includes a tabular member 102 (attaching member)and the speaker unit 30. In the embodiments described above, examplesare shown in which the box-shaped outer box 2 is used as the attachingmember. As shown in FIG. 13, in an example of the present embodiment,the tabular member 102, instead of the outer box 2, is used as theattaching member (it can also be understood as a configuration in whichthe outer box 2 has the front board 2 a alone).

The tabular member 102 of the present embodiment is substantiallyrectangular-shaped. As shown in FIG. 13, the tabular member 102 is onthe negative Z-axis side relative to the speaker unit 30 and issubstantially parallel to the sound emitting plane. In other words, thetabular member 102 corresponds to a portion of the attaching member onthe sound emitting portion 30 a side (first portion of the attachingmember). The tabular member 102 can also be understood as the attachingmember having the first portion alone. In the tabular member 102, anopening 120 is formed (shown with dashed lines in FIG. 13) that exposesthe sound emitting portion 30 a of the speaker unit 30 and correspondsto the shape of the sound emitting portion 30 a. On the four corners ofthe inner surface of the tabular member 102 (the surface on a speakerunit 30 side), there are formed holding parts 24 that each have, forexample, a concave shape.

The speaker unit 30 has, in addition to the sound emitting portion 30 a,which is a portion that vibrates in accordance with audio signals togenerate sounds (e.g., a diaphragm), a frame 71 by which the soundemitting portion 30 a is fixed in a way that enables the sound emittingportion 30 a to vibrate. The frame 71 has a housing portion 71 a thathouses the sound emitting portion 30 a (in FIG. 13, the position of thesound emitting portion 30 a is shown with dotted lines) and asubstantially rectangular-shaped tabular portion 71 b that issubstantially parallel to the sound emitting plane. As shown in FIG. 13,the housing portion 71 a of the present embodiment has its central axisparallel to the Z-axis, and has a shape of truncated cone dilatingtoward the negative Z-axis direction (the direction towards the soundemitting plane). The tabular portion 71 b of the frame 71 has an opening72 (shown with dashed lines in FIG. 13) that exposes the sound emittingportion 30 a. The tabular portion 71 b is provided on the negativeZ-axis side relative to the housing portion 71 a (on a tabular member102 side). On the surface of the tabular portion 71 b on the tabularmember 102 side, there are formed holding parts 73 that, for example,protrude from the surface.

FIG. 14 shows a schematic diagram showing an example of a cross-sectionof the sound output device 1 when the sound output device 1 is viewedfrom the positive Y-axis side. For brevity, illustration of the holdingparts 24 and 73, and details of the speaker unit 30, such as the frame71, etc., are omitted in FIG. 14. Such simplified illustration alsoapplies to FIG. 16 and FIG. 17, which are described later.

As shown in FIGS. 13 and 14, the vibration dampers 50 (separatingmembers) lie between the tabular member 102 and the speaker unit 30. Thevibration dampers 50 lie between the tabular member 102 and the speakerunit 30, separating them to absorb vibrations of the speaker unit 30.Similarly to the above-described embodiments, in this embodiment, acoiled spring member is used as an example of a vibration damper 50. Oneend of a vibration damper 50 is attached to a holding part 24 formed onthe tabular member 102, and the other end of the vibration damper 50 isattached to a holding part 73 formed on the speaker unit 30 (tabularportion 71 b). More specifically, a holding part 73 that, for example,protrudes from the surface is inserted into one end of a spring member,and the other end of the spring member is inserted into the concave partof a, for example, concave-shaped holding part 24. In the presentembodiment, the vibration dampers 50 also serve to fix the speaker unit30 to the tabular member 102.

In the following, the description of the holding parts (24 and 73) maybe omitted for brevity. For example, the description that “the vibrationdampers 50 lie between the tabular member 102 and the speaker unit 30”means that “the vibration dampers 50 lie between the holding parts 24 onthe tabular member 102 and the holding part 73 on the speaker unit 30.”

Between the tabular member 102 and the speaker unit 30 (more precisely,the tabular portion 71 b of the frame 71 of the speaker unit 30), thereis provided a sealing member 80. The sealing member 80 seals a gapbetween the periphery of the opening 120 in the tabular member 102 andthe periphery of the sound emitting portion 30 a (more precisely, theperiphery of the opening 72 in the tabular portion 71 b). Morespecifically, the sealing member 80 is a tubular member that liesbetween the tabular member 102 and the tabular portion 71 b. One end ofthe sealing member 80 is attached on the periphery of the opening 120 inthe tabular member 102, and the other end is attached on the peripheryof the opening 72 in the tabular portion 71 b. The opening 72 in thetabular portion 71 b and the opening 120 in the tabular member 102communicate with each other via the space inside the sealing member 80.Accordingly, sounds generated by the sound emitting portion 30 a passthrough the opening 72 in the tabular portion 71 b, the space inside thesealing member 80, and the opening 120 in the tabular member 102, to beemitted to the external space. In other words, the sealing member 80seals, from the external space, the space extending from the opening 72in the tabular portion 71 b to the opening 120 in the tabular member102.

The sealing member 80 is a member that reduces transmission of sounds,and in the present embodiment, a rubber member is used as an example ofthe sealing member 80.

As shown in FIG. 14, the sound output device 1 is attached to a freelychosen object 7, such as the interior of a car. More specifically, thesound output device 1 is attached to the interior of a car such that theouter surface of the tabular member 102 (the surface opposite to thespeaker unit 30 side), in which the opening 120 is formed, faces theback side of the interior. In this way, the sound emitting portion 30 aof the speaker unit 30 faces toward the inside of the car. In otherwords, the tabular member 102 serves as an attaching member thatattaches the speaker unit 30 to the object 7. The object 7 may be, forexample, the ceiling of the car's interior (e.g., a part near a roomlamp and/or a map lamp), a dashboard, or a door.

For brevity, only a portion of the object 7, to which the sound outputdevice 1 is attached, is illustrated in FIG. 14. Such simplifiedillustration also applies to FIG. 16 and FIG. 17.

In this embodiment, as described above, the speaker unit 30 is attachedto the tabular member 102 (attaching member) with the vibration dampers50 (separating member) provided therebetween to separate them. In thisway, when the speaker unit 30 generates sounds, vibrations generated bythe speaker unit 30 are absorbed by the vibration dampers 50. Thus, in acase in which the sound output device 1 is attached to an object 7,e.g., the interior of a car, vibrations (vibrations generated by thespeaker unit 30) that are transmitted to the object 7 via the tabularmember 102 are reduced, and consequently, noise that is caused by thevibrations can be reduced. Moreover, since the sealing member 80 sealsthe gap between the periphery of the opening 120 in the tabular member102 and the periphery of the sound emitting portion 30 a, sounds thatare emitted from the rear portion 30 b of the speaker unit 30 andtransmitted to the sound emitting portion 30 a side are reduced. Thatis, the sneaking of the sounds emitted from the rear portion 30 b of thespeaker unit 30 to the sound emitting portion 30 a side is lessened. Inother words, the sealing member 80 serves similarly to the inner box 32of the first to the third embodiments in reducing the sneaking of suchsounds, and thus achieves a similar advantageous effect.

The sound output device 1 of the present embodiment does not include amicrophone. In a case in which a microphone is provided, it may beprovided near the speaker unit 30. In the configuration of the presentembodiment, vibrations that are transmitted to the object 7 are reduced,and thus, noise that is caused by the vibrations and is transmitted tothe microphone near the speaker unit 30 is also reduced. Accordingly, inthe present embodiment, in addition to the above-described advantageouseffect, an advantageous effect of lessening degradation ofecho-cancellation performance is also achieved.

In this embodiment, an exemplary configuration is described in whichmaterial used for a vibration damper 50 is a spring. However, materialused for a vibration damper 50 is not limited to a spring and may be anymaterial that absorbs vibrations. Material used for a vibration damper50 may be any elastic material other than a spring (e.g., a sponge,resin), or any other material (e.g., gel).

In the exemplary configuration described above, the sealing member 80 isprovided between the periphery of the opening 120 in the tabular member102 and the periphery of the sound emitting portion 30 a. However, thesealing member 80 may be provided at any position that enables thereduction in the sounds that sneak to the sound emitting portion 30 aside after being emitted from the rear portion 30 b. In the exampleshown in FIG. 13, the sealing member 80 is disposed on a side of thecentral axis of the speaker unit 30 along the X-axis relative to thevibration dampers 50 (i.e., disposed inward relative to the vibrationdampers 50). However, the sealing member 80 may be disposed farther fromthe central axis than the vibration dampers 50 (i.e., disposed outwardrelative to the vibration dampers 50). In FIGS. 13 and 14, an example isshown in which the attaching member (the tabular member 102) is tabular.However, the attaching member may have a front board 2 a and side boards2 c, such as those described in the first embodiment. In this case, thesealing member 80 may be provided between the side boards 2 c and thespeaker unit 30 (e.g., the tabular portion 71 b of the frame 71).

In the above description, an example of a tabular portion 71 b having asubstantially tabular shape is described. However, the tabular portion71 b may have, for example, a round shape or any other shape.Additionally, the surface of the tabular portion 71 b does not need tobe flat.

Similarly, in the above description, an example of a housing portion 71a having a truncated cone shape is described. However, the housingportion 71 a may have a truncated square pyramid shape, a cuboid shape,or any other shape.

In the above example, the vibration dampers 50 serve to fix the speakerunit 30 to the tabular member 102. Alternatively, the sealing member 80may fix the speaker unit 30 to the tabular member 102. Alternatively,any other member may fix the speaker unit 30 to the tabular member 102,as long as the function of reducing vibrations transmitted to the object7 is not hampered.

Modifications of Fourth Embodiment

The sound output device 1 according to the fourth embodiment can bemodified in a variety of ways. Two or more modes freely selected fromthe modes described below may be appropriately combined as long as theyare not in conflict with one another.

Modification Mode 1

In the fourth embodiment, an exemplary configuration is described inwhich material used for the sealing member 80 is rubber. However,material used for the sealing member 80 may be any other material thatreduces transmission of sounds, such as grease or closed-pore sponge.

FIG. 15 shows a schematic configuration of a sound output device 1according to mode 1. In mode 1, grease is used for the sealing member80. On the surface of the tabular member 102 on the speaker unit 30side, an inner cylinder 401 and an outer cylinder 402 that has a greaterinner diameter than the outer diameter of the inner cylinder 401 areformed concentrically on the periphery of the opening 120. On thesurface of the tabular portion 71 b of the speaker unit 30 on thetabular member 102 side, a cylindrical portion 501 is formedconcentrically on the periphery of the opening 72. The inner diameter ofthe cylindrical portion 501 is greater than the outer diameter of theinner cylinder 401, and the outer diameter of the cylindrical portion501 is smaller than the inner diameter of the outer cylinder 402. Thelength in the Z-axis direction (the height) of each of the innercylinder 401, the outer cylinder 402, and the cylindrical portion 501 issmaller than the length in the Z-axis direction of a separating memberlying between the tabular member 102 and the speaker unit 30.

As shown in the figure, in a state in which the sound output device 1has been assembled, the cylindrical portion 501 is provided between theinner cylinder 401 and the outer cylinder 402. In other words, the innercylinder 401 and the outer cylinder 402 are separated from each other tothe extent that the cylindrical portion 501 can be providedtherebetween. The space between the inner cylinder 401 and the outercylinder 402 is filled with grease (sealing member 80) to seal the gapbetween the periphery of the opening 120 in the tabular member 102 andthe periphery of the sound emitting portion 30 a (more precisely, theperiphery of the opening 72 in the tabular portion 71 b). For example,the sound output device 1 may be assembled by pushing the cylindricalportion 501 into the space between the inner cylinder 401 and the outercylinder 402 after grease (sealing member 80) has been poured into thespace between the inner cylinder 401 and the outer cylinder 402.

In the above configuration, advantageous effects similar to those of thefourth embodiment are achieved.

Modification Mode 2

FIG. 16 is a schematic diagram showing an example of a cross-section ofa sound output device 1 according to mode 2, when the sound outputdevice 1 is viewed from the positive Y-axis side. As shown in thefigure, the sound output device 1 according to mode 2 includes, insteadof the vibration dampers 50 and the sealing member 80, a vibrationdamper 53 (separating member). The vibration damper 53 serves as thevibration dampers 50 and the sealing member 80 described in the fourthembodiment. The vibration damper 53 lies between the tabular member 102and the speaker unit 30, separating them to absorb vibrations of thespeaker unit 30. The vibration damper 53 is a member that reducestransmission of sounds and seals the gap between the tabular member 102and the speaker unit 30. More specifically, the vibration damper 53seals the gap between the periphery of the opening 120 in the tabularmember 102 and the periphery of the sound emitting portion 30 a of thespeaker unit 30 (more precisely, the periphery of the opening 72 in thetabular portion 71 b). The vibration damper 53 is, for example, a rubbermember.

In mode 2, the holding parts 24 are not essential for the tabular member102, and the holding parts 73 are not essential for the speaker unit 30.

Also in the above configuration, advantageous effects similar to thoseof the fourth embodiment are achieved. When the speaker unit 30 emitssounds, vibrations generated by the speaker unit 30 are absorbed by thevibration damper 53. Thus, in a case in which the sound output device 1is attached to the object 7, an example of which is the interior of acar, vibrations (vibrations generated by the speaker unit 30) that aretransmitted to the object 7 via the tabular member 102 are reduced, andconsequently, noise that is caused by the vibrations can be reduced.Moreover, since the vibration damper 53 seals the gap between theperiphery of the opening 120 in the tabular member 102 and the peripheryof the sound emitting portion 30 a, sounds that are emitted from therear portion 30 b of the speaker unit 30 and are then transmitted to aside of the sound emitting portion 30 a of the speaker unit 30 arereduced. That is, the sneaking of the sounds emitted from the rearportion 30 b of the speaker unit 30 to the sound emitting portion 30 aside is lessened. Furthermore, since the vibration damper 53 serves asthe vibration dampers 50 and the sealing member 80, compared with aconfiguration in which the vibration dampers 50 and the sealing member80 are provided separately, the number of parts that are used tomanufacture the sound output device 1 is reduced, and thus, man-hoursrequired for manufacturing the sound output device 1 can be reduced. Asa result, the cost of manufacturing the sound output device 1 can bereduced.

Modification Mode 3

FIG. 17 is a schematic diagram showing an example of a cross-section ofa sound output device 1 according to mode 3, when the sound outputdevice 1 is viewed from the positive Y-axis side. As shown in thefigure, the sound output device 1 according to mode 3 includes,similarly to the sound output device 1 according to the fourthembodiment, the speaker unit 30, the vibration dampers 50 (separatingmember), and the sealing member 80. The sound output device 1 accordingto mode 3, however, does not include the tabular member 102 (attachingmember). In mode 3, the vibration dampers 50 lie between the object 7,to which the sound output device 1 is attached, and the speaker unit 30,separating them to absorb vibrations of the speaker unit 30. The sealingmember 80 seals the gap between the object 7 (more precisely, theperiphery of an opening provided in the object 7, wherein the opening isfor enabling sounds generated by the sound emitting portion 30 a to passthrough) and the speaker unit 30 (more precisely, the periphery of theopening 72 in the tabular portion 71 b).

In the above configuration, advantageous effects similar to those of thefourth embodiment are achieved. When the speaker unit 30 emits sounds,vibrations generated by the speaker unit 30 are absorbed by thevibration dampers 50. Thus, in a case in which the sound output device 1is attached to the object 7, an example of which is the interior of acar, vibrations (vibrations generated by the speaker unit 30) that aretransmitted to the object 7 via the vibration dampers 50 are reduced,and consequently, noise that is caused by the vibrations can be reduced.Moreover, since the sealing member 80 seals the gap between the openingin the object 7 and the periphery of the sound emitting portion 30 a,sounds that are emitted from the rear portion 30 b of the speaker unit30 and are then transmitted to a side of the sound emitting portion 30 aof the speaker unit 30 are reduced. That is, the sneaking of the soundsemitted from the rear portion 30 b of the speaker unit 30 to the soundemitting portion 30 a side is lessened. Furthermore, in theconfiguration of mode 3, the speaker unit 30 is attached to the object 7without the attaching member (tabular member 102) lying therebetween.Thus, compared with a configuration in which an attaching member isprovided, the number of parts that are used to manufacture the soundoutput device 1 is reduced, and thus, man-hours required formanufacturing the sound output device 1 can be reduced. As a result, thecost of manufacturing the sound output device 1 can be reduced.

In the fourth embodiment and its modification modes, a space in theobject 7 to which the sound output device 1 is attached can serve as anenclosure that lessens the sneaking of the sounds emitted from the rearportion 30 b of the speaker unit 30 to the sound emitting portion 30 aside. Here, the object 7 is, for example, the interior of a car, and thespace in the object 7 is, for example, the space inside the interior ofthe car.

The following aspects or modes are derived from the above-mentionedembodiments and modifications.

A sound output device according to a first aspect of the presentinvention includes: a speaker unit that has a sound emitting portion; anattaching member by which the speaker unit is attached to an object; aseparating member that is provided between the speaker unit and theattaching member to separate the speaker unit from the attaching member;and a sealing member that is provided between the speaker unit and theattaching member to reduce a sound that is emitted from a side of thespeaker unit opposite to the sound emitting portion and is transmittedto a sound emitting portion side. The attaching member has a firstportion on a side of the sound emitting portion of the speaker unit, andthe first portion of the attaching member has an opening thatcorresponds to the sound emitting portion. One end of the separatingmember is attached to the speaker unit and the other end of theseparating member is attached to the attaching member, and one end ofthe sealing member is attached to the speaker unit and the other end ofthe sealing member is attached to the attaching member.

A sound output device according to a second aspect of the presentinvention includes: a speaker unit that has a sound emitting portion; anattaching member by which the speaker unit is attached to an object; anda separating member that is provided between the speaker unit and theattaching member to separate the speaker unit from the attaching member.The separating member reduces a sound that is emitted from a side of thespeaker unit opposite to the sound emitting portion and is transmittedto a sound emitting portion side. One end of the separating member isattached to the speaker unit and the other end of the separating memberis attached to the attaching member. The attaching member has a firstportion on a side of the sound emitting portion of the speaker unit, andthe first portion of the attaching member has an opening thatcorresponds to the sound emitting portion.

A sound output device according to a third aspect of the presentinvention includes: a chassis that houses a speaker unit that has asound emitting portion; an attaching member by which the chassis isattached to an object; and separating members that are provided betweenthe chassis and the attaching member to separate the chassis from theattaching member. The chassis has a first portion on a side of the soundemitting portion of the speaker unit, the attaching member has a firstportion on a side of the sound emitting portion of the speaker unit, andthe first portion of the chassis and the first portion of the attachingmember each have an opening that corresponds to the sound emittingportion.

In any of the configurations of the sound output devices according tothe first to third aspects, when a sound is emitted from the speakerunit, vibrations generated by the speaker unit are absorbed by theseparating member. Accordingly, in a case in which the sound outputdevice is attached to, for example, the interior of a car, vibrations(vibrations transmitted from the speaker unit) that are transmitted tothe car's interior (i.e., transmitted outside from the sound outputdevice) via the attaching member are reduced, resulting in a reductionin noise generated by the vibrations.

In a mode of the third aspect of the invention, the attaching member hasa second portion that is provided on a side opposite to the soundemitting portion of the speaker unit (on a side of a rear portion of thespeaker unit), and which second portion of the attaching member may havean opening. The attaching member may have a third portion on a sidewallside of the speaker unit and, instead of or in addition to the openingin the second portion, may have an opening in the third portion. In thismode, an opening is provided in at least one of the second portion andthe third portion of the attaching member. As a result, even in a casein which the chassis that houses the speaker unit is distorted due togeneration of sound, the pressure in a hollow between the chassis andthe attaching member will not increase. Thus, unnecessary distortion inthe attaching member can be minimized.

In a mode of the third aspect of the invention, the separating membersare disposed between the first portion of the chassis and the firstportion of the attaching member. In this mode, since the separatingmember is disposed on the same side as the sound emitting portion of thespeaker unit, vibrations transmitted from the speaker unit are reducedeffectively.

In a mode of the third aspect of the invention, the separating membersare each a spring member, and the sound output device may furtherinclude another spring member that is provided between the chassis andthe attaching member, the other spring member having a larger springconstant than the spring member. In this mode, even when an excessiveacceleration is applied to the chassis, a vibration-caused collisionbetween the chassis and the attaching member can be suppressed.

In a mode of the third aspect of the invention, the separating membersmay each be a non-linear spring member with a spring constant thatincreases with an increasing load. In this mode, when an excessiveacceleration is applied to the chassis, the spring constant willincrease before the chassis collides with the attaching member.Therefore, a collision between the chassis and the attaching member canbe suppressed.

In a mode of the third aspect of the invention, the chassis does notneed to have openings other than the opening in the first portion. Inanother mode, the chassis may have a second portion that is provided ona side opposite to the sound emitting portion of the speaker unit, andthe second portion of the chassis may have an opening. In yet anothermode, the chassis does not need to have a portion that is provided on aside opposite to the sound emitting portion of the speaker unit (thechassis does not need to have a second portion).

In a mode of the third aspect of the invention, in a central-axisdirection of the speaker unit, neither the length of the chassis nor thelength of the attaching member is greater than the length of the speakerunit. In this mode, in the central-axis direction of the speaker unit,the sound output device can have the same length as the speaker unit.Thus, compared with a sound output device with a chassis or an attachingmember that is longer than a speaker unit, the sound output deviceaccording to this mode is reduced in size, assuming that the lengths ofthe speaker units of these sound output devices are the same.

In a mode of the third aspect of the invention, the chassis may have asecond portion that is provided on a side opposite to the sound emittingportion of the speaker unit (on a side of the rear portion of thespeaker unit), the attaching member may have a second portion that isprovided on a side opposite to the sound emitting portion of the speakerunit, and the separating members may be disposed between the secondportion of the chassis and the second portion of the attaching member.In another mode, the chassis may have a third portion on a sidewall sideof the speaker unit, the attaching member may have a second portion thatis provided on a side opposite to the sound emitting portion of thespeaker unit, and the separating members may be disposed between thethird portion of the chassis and the second portion of the attachingmember.

In a mode of the third aspect of the invention, the sound output devicemay further include a sealing member that reduces transmission of asound, wherein the sealing member is provided between the first portionof the chassis and the first portion of the attaching member. In thismode, a sound is reduced that is emitted from a side opposite to thesound emitting portion of the speaker unit (from the rear portion of thespeaker unit), passes through the space between the chassis and theattaching member, and is then emitted to a side of the sound emittingportion of the speaker unit. In other words, the sneaking of the soundemitted from the rear portion of the speaker unit to the front islessened.

DESCRIPTION OF REFERENCE SIGNS

-   -   1 . . . sound output device; 2 . . . outer box (attaching        member); 2 a . . . front board of the outer box (first portion        of the attaching member); 2 b . . . back board of the outer box        (second portion of the attaching member); 2 c . . . side board        of the outer box (third portion of the attaching member); 3 . .        . loudspeaker; 4 . . . microphone; 7 . . . object; 20, 21, 22 .        . . opening; 23 . . . recessed portion; 24, 25, 26 . . . holding        part; 30 . . . speaker unit; 30 a . . . sound emitting portion        of the speaker unit; 30 b . . . rear portion of the speaker        unit; 30 c . . . sidewall of the speaker unit; 32 . . . inner        box (chassis); 32 a . . . front portion of the inner box (first        portion of the chassis); 32 b . . . back portion of the inner        box (second portion of the chassis); 32 c . . . side portion of        the inner box (third portion of the chassis); 33, 34 . . .        holding part; 35, 36 . . . opening; 50, 51 . . . vibration        damper (separating member); 52 . . . vibration damper (another        spring member); 53 . . . vibration damper (separating member);        60 . . . signal processing IC; 71 . . . frame; 71 a . . .        housing portion of the frame; 71 b . . . tabular portion of the        frame; 72 . . . opening; 73 . . . holding part; 80 . . . sealing        member; 102 . . . tabular member (attaching member); 120 . . .        opening; 301 . . . movable portion of the speaker unit; 302 . .        . non-movable portion of the speaker unit; 303 . . . elastic        member of the speaker unit; 401 . . . inner cylinder; 402 . . .        outer cylinder; 501 . . . cylindrical portion.

What is claimed is:
 1. A sound output device attachable to an objectincluding a first opening that allows emission of sound, the soundoutput device comprising: a speaker unit that has a sound emittingportion; an attaching member by which the speaker unit is attached tothe object; and at least one separating member comprising a springconfigured to absorb vibrations of the speaker unit, the at least oneseparating member being provided between the speaker unit and theattaching member to separate the speaker unit from the attaching member,wherein the attaching member has a first portion on a side of the soundemitting portion of the speaker unit, wherein the first portion of theattaching member has a second opening that corresponds to the soundemitting portion, wherein one end of the at least one separating memberis attached to the speaker unit and the other end of the at least oneseparating member is attached to the attaching member, and wherein thefirst portion of the attaching member is configured to attach to theobject, with the second opening aligned with the first opening to allowsound to emit to outside of the object through the second and firstopenings in this order in a state where the sound output device isattached to the object.
 2. The sound output device according to claim 1,further comprising: a sealing member that is provided between thespeaker unit and the at least one attaching member to reduce a soundthat is emitted from a side of the speaker unit opposite to the soundemitting portion and is transmitted to a sound emitting portion side. 3.The sound output device according to claim 1, wherein: the at least oneseparating member reduces a sound that is emitted from a side of thespeaker unit opposite to the sound emitting portion and is transmittedto a sound emitting portion side.